1 /* 2 * OSS handling 3 * Written by Joshua M. Thompson (funaho@jurai.org) 4 * 5 * 6 * This chip is used in the IIfx in place of VIA #2. It acts like a fancy 7 * VIA chip with prorammable interrupt levels. 8 * 9 * 990502 (jmt) - Major rewrite for new interrupt architecture as well as some 10 * recent insights into OSS operational details. 11 * 990610 (jmt) - Now taking full advantage of the OSS. Interrupts are mapped 12 * to mostly match the A/UX interrupt scheme supported on the 13 * VIA side. Also added support for enabling the ISM irq again 14 * since we now have a functional IOP manager. 15 */ 16 17 #include <linux/types.h> 18 #include <linux/kernel.h> 19 #include <linux/mm.h> 20 #include <linux/delay.h> 21 #include <linux/init.h> 22 23 #include <asm/bootinfo.h> 24 #include <asm/macintosh.h> 25 #include <asm/macints.h> 26 #include <asm/mac_via.h> 27 #include <asm/mac_oss.h> 28 29 int oss_present; 30 volatile struct mac_oss *oss; 31 32 static irqreturn_t oss_irq(int, void *); 33 static irqreturn_t oss_nubus_irq(int, void *); 34 35 extern irqreturn_t via1_irq(int, void *); 36 37 /* 38 * Initialize the OSS 39 * 40 * The OSS "detection" code is actually in via_init() which is always called 41 * before us. Thus we can count on oss_present being valid on entry. 42 */ 43 44 void __init oss_init(void) 45 { 46 int i; 47 48 if (!oss_present) return; 49 50 oss = (struct mac_oss *) OSS_BASE; 51 52 /* Disable all interrupts. Unlike a VIA it looks like we */ 53 /* do this by setting the source's interrupt level to zero. */ 54 55 for (i = 0; i <= OSS_NUM_SOURCES; i++) { 56 oss->irq_level[i] = OSS_IRQLEV_DISABLED; 57 } 58 /* If we disable VIA1 here, we never really handle it... */ 59 oss->irq_level[OSS_VIA1] = OSS_IRQLEV_VIA1; 60 } 61 62 /* 63 * Register the OSS and NuBus interrupt dispatchers. 64 */ 65 66 void __init oss_register_interrupts(void) 67 { 68 if (request_irq(OSS_IRQLEV_SCSI, oss_irq, 0, "scsi", (void *)oss)) 69 pr_err("Couldn't register %s interrupt\n", "scsi"); 70 if (request_irq(OSS_IRQLEV_NUBUS, oss_nubus_irq, 0, "nubus", 71 (void *)oss)) 72 pr_err("Couldn't register %s interrupt\n", "nubus"); 73 if (request_irq(OSS_IRQLEV_SOUND, oss_irq, 0, "sound", (void *)oss)) 74 pr_err("Couldn't register %s interrupt\n", "sound"); 75 if (request_irq(OSS_IRQLEV_VIA1, via1_irq, 0, "via1", (void *)via1)) 76 pr_err("Couldn't register %s interrupt\n", "via1"); 77 } 78 79 /* 80 * Initialize OSS for Nubus access 81 */ 82 83 void __init oss_nubus_init(void) 84 { 85 } 86 87 /* 88 * Handle miscellaneous OSS interrupts. Right now that's just sound 89 * and SCSI; everything else is routed to its own autovector IRQ. 90 */ 91 92 static irqreturn_t oss_irq(int irq, void *dev_id) 93 { 94 int events; 95 96 events = oss->irq_pending & (OSS_IP_SOUND|OSS_IP_SCSI); 97 if (!events) 98 return IRQ_NONE; 99 100 #ifdef DEBUG_IRQS 101 if ((console_loglevel == 10) && !(events & OSS_IP_SCSI)) { 102 printk("oss_irq: irq %d events = 0x%04X\n", irq, 103 (int) oss->irq_pending); 104 } 105 #endif 106 /* FIXME: how do you clear a pending IRQ? */ 107 108 if (events & OSS_IP_SOUND) { 109 oss->irq_pending &= ~OSS_IP_SOUND; 110 /* FIXME: call sound handler */ 111 } else if (events & OSS_IP_SCSI) { 112 oss->irq_pending &= ~OSS_IP_SCSI; 113 generic_handle_irq(IRQ_MAC_SCSI); 114 } else { 115 /* FIXME: error check here? */ 116 } 117 return IRQ_HANDLED; 118 } 119 120 /* 121 * Nubus IRQ handler, OSS style 122 * 123 * Unlike the VIA/RBV this is on its own autovector interrupt level. 124 */ 125 126 static irqreturn_t oss_nubus_irq(int irq, void *dev_id) 127 { 128 int events, irq_bit, i; 129 130 events = oss->irq_pending & OSS_IP_NUBUS; 131 if (!events) 132 return IRQ_NONE; 133 134 #ifdef DEBUG_NUBUS_INT 135 if (console_loglevel > 7) { 136 printk("oss_nubus_irq: events = 0x%04X\n", events); 137 } 138 #endif 139 /* There are only six slots on the OSS, not seven */ 140 141 i = 6; 142 irq_bit = 0x40; 143 do { 144 --i; 145 irq_bit >>= 1; 146 if (events & irq_bit) { 147 oss->irq_pending &= ~irq_bit; 148 generic_handle_irq(NUBUS_SOURCE_BASE + i); 149 } 150 } while(events & (irq_bit - 1)); 151 return IRQ_HANDLED; 152 } 153 154 /* 155 * Enable an OSS interrupt 156 * 157 * It looks messy but it's rather straightforward. The switch() statement 158 * just maps the machspec interrupt numbers to the right OSS interrupt 159 * source (if the OSS handles that interrupt) and then sets the interrupt 160 * level for that source to nonzero, thus enabling the interrupt. 161 */ 162 163 void oss_irq_enable(int irq) { 164 #ifdef DEBUG_IRQUSE 165 printk("oss_irq_enable(%d)\n", irq); 166 #endif 167 switch(irq) { 168 case IRQ_MAC_SCC: 169 oss->irq_level[OSS_IOPSCC] = OSS_IRQLEV_IOPSCC; 170 break; 171 case IRQ_MAC_ADB: 172 oss->irq_level[OSS_IOPISM] = OSS_IRQLEV_IOPISM; 173 break; 174 case IRQ_MAC_SCSI: 175 oss->irq_level[OSS_SCSI] = OSS_IRQLEV_SCSI; 176 break; 177 case IRQ_NUBUS_9: 178 case IRQ_NUBUS_A: 179 case IRQ_NUBUS_B: 180 case IRQ_NUBUS_C: 181 case IRQ_NUBUS_D: 182 case IRQ_NUBUS_E: 183 irq -= NUBUS_SOURCE_BASE; 184 oss->irq_level[irq] = OSS_IRQLEV_NUBUS; 185 break; 186 #ifdef DEBUG_IRQUSE 187 default: 188 printk("%s unknown irq %d\n", __func__, irq); 189 break; 190 #endif 191 } 192 } 193 194 /* 195 * Disable an OSS interrupt 196 * 197 * Same as above except we set the source's interrupt level to zero, 198 * to disable the interrupt. 199 */ 200 201 void oss_irq_disable(int irq) { 202 #ifdef DEBUG_IRQUSE 203 printk("oss_irq_disable(%d)\n", irq); 204 #endif 205 switch(irq) { 206 case IRQ_MAC_SCC: 207 oss->irq_level[OSS_IOPSCC] = OSS_IRQLEV_DISABLED; 208 break; 209 case IRQ_MAC_ADB: 210 oss->irq_level[OSS_IOPISM] = OSS_IRQLEV_DISABLED; 211 break; 212 case IRQ_MAC_SCSI: 213 oss->irq_level[OSS_SCSI] = OSS_IRQLEV_DISABLED; 214 break; 215 case IRQ_NUBUS_9: 216 case IRQ_NUBUS_A: 217 case IRQ_NUBUS_B: 218 case IRQ_NUBUS_C: 219 case IRQ_NUBUS_D: 220 case IRQ_NUBUS_E: 221 irq -= NUBUS_SOURCE_BASE; 222 oss->irq_level[irq] = OSS_IRQLEV_DISABLED; 223 break; 224 #ifdef DEBUG_IRQUSE 225 default: 226 printk("%s unknown irq %d\n", __func__, irq); 227 break; 228 #endif 229 } 230 } 231 232 /* 233 * Clear an OSS interrupt 234 * 235 * Not sure if this works or not but it's the only method I could 236 * think of based on the contents of the mac_oss structure. 237 */ 238 239 void oss_irq_clear(int irq) { 240 /* FIXME: how to do this on OSS? */ 241 switch(irq) { 242 case IRQ_MAC_SCC: 243 oss->irq_pending &= ~OSS_IP_IOPSCC; 244 break; 245 case IRQ_MAC_ADB: 246 oss->irq_pending &= ~OSS_IP_IOPISM; 247 break; 248 case IRQ_MAC_SCSI: 249 oss->irq_pending &= ~OSS_IP_SCSI; 250 break; 251 case IRQ_NUBUS_9: 252 case IRQ_NUBUS_A: 253 case IRQ_NUBUS_B: 254 case IRQ_NUBUS_C: 255 case IRQ_NUBUS_D: 256 case IRQ_NUBUS_E: 257 irq -= NUBUS_SOURCE_BASE; 258 oss->irq_pending &= ~(1 << irq); 259 break; 260 } 261 } 262 263 /* 264 * Check to see if a specific OSS interrupt is pending 265 */ 266 267 int oss_irq_pending(int irq) 268 { 269 switch(irq) { 270 case IRQ_MAC_SCC: 271 return oss->irq_pending & OSS_IP_IOPSCC; 272 break; 273 case IRQ_MAC_ADB: 274 return oss->irq_pending & OSS_IP_IOPISM; 275 break; 276 case IRQ_MAC_SCSI: 277 return oss->irq_pending & OSS_IP_SCSI; 278 break; 279 case IRQ_NUBUS_9: 280 case IRQ_NUBUS_A: 281 case IRQ_NUBUS_B: 282 case IRQ_NUBUS_C: 283 case IRQ_NUBUS_D: 284 case IRQ_NUBUS_E: 285 irq -= NUBUS_SOURCE_BASE; 286 return oss->irq_pending & (1 << irq); 287 break; 288 } 289 return 0; 290 } 291